All of the sudden, life is really good for John McCain:

The Republican National Convention has given John McCain and his party a significant boost, a USA TODAY/Gallup Poll taken over the weekend shows, as running mate Sarah Palin helps close an “enthusiasm gap” that has dogged the GOP all year.

McCain leads Democrat Barack Obama by 50%-46% among registered voters, the Republican’s biggest advantage since January and a turnaround from the USA TODAY poll taken just before the convention opened in St. Paul. Then, he lagged by 7 percentage points.

[. . .]

In the new poll, taken Friday through Sunday, McCain leads Obama by 54%-44% among those seen as most likely to vote. The survey of 1,022 adults, including 959 registered voters, has a margin of error of +/– 3 points for both samples.

Of course, this is immediately after a convention, so whatever bounce there is may well dissipate soon. That is the nature of bounces.

Then again, it is worth noting that at times, bounces do not dissipate. Something that ought to worry the Obama campaign.